This invention relates generally to an air-fuel mixture supplying device for internal combustion engines and more specifically relates to improvements in pulverization of fuel and fuel distribution among cylinders of the engine.
In conventional air-fuel mixture supplying devices as shown in FIGS. 1, 2 and 3, injector valves 200 and 200' have fuel ejection ports 102 and 102' which open to a venturi portion 103 downstream of the throttle valve 101 and deviate by .epsilon. from each other as best illustrated in FIG. 1. The fuel is introduced into the fuel chamber 301 from the passage 303, and the return fuel is also introduced to the fuel chamber 301 through the passage 304. The fuel in the chamber 301 is then led to the inlets of the injector valves 200 and 200' through a passage 305. When the coils 204 and 204' of the injector valves 200 and 200' are energized, plungers 201 and 201' are retracted against the force of springs 205 and 205' thereby opening the delivery ports 202 and 202' from which a required amount of fuel corresponding to the quantity of air drawn into the engine is ejected.
Ejected fuel is pulverized by bleed air in the atomizing chamber and further pulverized while passing through sonic nozzles 203 and 203' before being ejected from the ejection ports 102 and 102'.
Since in the conventional method the ejection speed of fuel from ejection ports 102 and 102' is large, the ejected fuel does not easily mix with the air coming through the throttle valve 101. Further, since the ejection ports face each other in such a way that their center lines deviate from each other, the pulverized fuel particles strike the internal surface of the venturi portion 103 and adhere to it so that the diameters of the atomized fuel particles become large before they reach the combustion chamber of the engine. This will adversely affect the fuel distribution among the cylinders of the engine.